Drive for talking machines



Oct. 7, 1930. L L. c. JAFFARD.

I 'DRIVE .FOR TALKING MACHINES Filed Sept. 14. 1929.

IIIII'IIIIIIIIIHI Patented Oct. 7, 1930 PATENT OFFICE!" LocIs' LAoRENrcHAnLns JAFraR-n; or rams, FRANCE 1 l DRIVE r012, rALKInG AoHiNEs Application filed September 14, 1929, Serial m. 392,711, and in lrance September 26,1928.

It has been proposed ottenand since a long tinre to replace the uniformrotary motion of phonograph records-by an accelerated movement which gives the needle a uniform glinear speed along the sound-record line. Thus if this linear speed is chosen equal to that corresponding totheinner radius of the recordscomnionly used, it is possible to considerably increase theduration of the play ing, this increase being'of the-order of the square of the outer radius; WVi-th moderate sized records recorded and playedthrough the'drive disclosed hercinbelow, I obtain a very great duration of play.

'lhe'manufacture and use of such records require the use of an improved driving gear [which transforms the usual easily obtained f'unii'orm speed of rotation into an accelerated frotarymotlon; According-to my lnventlon 2;)

this has been. provided by controlling the .turn-table'shaft of a talking machine, or recording device througha concave spindle rotating with a uniform speed, said spindle actuating the turn-table through its operating surface which is generated by the revolutionx'ofa curvewhaving an equation (E y constant round the axis of rotation of the quired data of the driving device. A suitable connection between the spindle and the turn-table shat-t ensure thedesired accelerated rotation? whereby the linear speed of the needle along the soundpathof the record to befrec'orded or played isfcaused' to be substantially constant,

" '1I"have' illustrated oi example a .form 'of execution of my invention v'vherein 4o.

asuitable;thread; i v r p 7 Fig; 1 is a vertical=cross-section-oi atallo ing-" machine provided with iny ii'nproved dliveg'; 1 3 f Fig. 1 2 ise horizontal projection thereof, 4 .The spindle'al'havinggaprogressively-increasing radius rotates at aiuniform angular speed ro'und its3axis 2l Itis provided with I acoiled groove 3"thelturns of which are close [sqftogetherand havearconstant pitch, In this :the spindle drives theturnt'able shaitthrough groove is wound a driving thread or wire 4: i wound oil a feed drum 5. A pulley 6 movlng round a stationary axis and a pulley 7 the axis of which is pivotally mounted onthe plate 8 are inserted for guiding the thread between the horizontal drum and the vertical spindle and giving it "the desired incline. The plate 8 is vertically movedby the vertical rotatable screws 9 and 10. 7

.The drum 5 is provided with a helical groove having the same pitch as that on spindie 1 and is secured to the stationary horizontal screw 11 the outer thread of which has the same pitch as the spindle and drum grooves and also as the vertical screws 9 and 10. The drum 5 is provided with two end flanges 12 and 13 each provided with two circular diametrically opposed apertures 14=-15 and 16-17. Through the corresponding alined apertures of the two flanges passthe rods 18 and-19 of a cage QO adapted mains in contact with the walls of one of the apertures through which it passes. The

simultaneously the spindle 1 and the vertical screws 9 and'lO controlling the pulleybearing plate 8. The part of the thread con-' necting the drum andspindle remains thus always substantially perpendicular to the axis of the spindle horizontal; when the drum 5 rotates it moves along its stationary horizontal screw 11 by an amount proporother exactly;the part of the thread which is being wound oil" the drum remains constantlyin the same vertical planesubstantially perpendicular to the axis of the drum.

Thus the portions of the thread near the winding and the unwinding points cannot be moved out of their groove.

ing determined by the shape given to the driving shaft 21 rotating uniformly controls p CBv andE being constants. I V

ture through which it passes and inside which it slides. Furthermore the rotary motion transmitted to the cage 20 is again trans mitted through the toothed wheel QI and the gearwork 22 to the turntable shaft and thereby to the recorder record blank.

dle on to the'drum through the agency ofthe pinion 28 and crank 27, the turn-table and motor remaining inoperative owing to the v corresponding 'free wheels 26, 24 whereas the crank remains stationary during playing owing-to the interpositionof its free wheel 25.

olutions required'for reaching the beginning of the said portion has been prevlously ascertained. 7

It 18 easy to see that the surface generated I by'th'e curvew y=constant, corresponding to the bottom of the guiding grooves ofthe spln- I dle is reallythe one giving to the disc a constant linear speed under the needle. 7 r

The iorm of the soundpath ofthe disc is diatv its arrival on the spindle is pro;

portional to the angular displacement of said i i spindle, if we'calli'x andfi the coordinates of a point of the curve generatingthe spindle, we have, with a convenient choice of the i a spiral of Archimedeswhose equation is:

9" being the radius vector, athe polanangie and K a constant.

j The constant linear, speed of the disc under 7 the needle being termed V, we have, r

V da V- ar or; taking Equation (1) into account:

a v- Iot 7 with a convenient choice oi theimargin of time, we conclude from-this last equation:

i The length (ll of the thread which during dtris unioldedtrom the drum 5 is propertional to a, so we may write i v The free wheels 24, 25, 26 inserted-as shownallow the V controlling thread'to be wound ofl'the'ispin But on theother hand, all is equal to th e corresponding are d8 of the guiding groove of the spindle; said are is itself substantially equalto the corresponding arc of the projection C ofsaid groove on aplan perpendicular to the spindle axis; let us term A and it the radius vector and polar angle of a point of said curve C,'we have;

but a is in'practice very small and so we may neglect it and write T r and since (Z8 is always equal to all, combi-] nation of (5) and (6), we obtain:

(9) R(AA) =constant for equation of the curve (3.. j

. v 90- v A. and F being constant; and then, by elimi natlon of 6 between (7 and (8), we obtain:

Now, since the vertical displacement of the c w g =constant q The. control of the spindle may beiefl'ected .byany spring or an electric motor actuating the spindle shaft and- .imparting thereto uniform rotary motion. 7 Other mechanical devices beyond that disclosed may obviously T J be used for driving the turn table shaft from u the spindle. For instanceone or more coils r of thedriving thread may be wound over a drum; and drive it frictionally. -The'druni woundifrom a second: spindle similar to the m '1051 andthus the equation of'said' generating I curvel's really:

i drives the turn-tableshaft as v 'p'recedently 7' througha suitable gearwork. i i

The thread passing over'the drum is n11 first one and rotating at:the same uniform What I claim is;

V speed the axes. of the two spindles being par-- i allel; ;The;:thread may thus -'be;altern'atively or taking into account the Equation (4)5 v \7 Wound f 'spindle onto the other.

1. rndriving devi'celfortalkingsound V V recording machines comprising arotary spindletofprogressively increasing radius the 45 equat1onX Y=constant, the axes ofY and if being respect vely'the axis of rotation and 5 a l ne perpendicular thereto, means for imsurface of which is generated by the revolution round its axis of rotation of a curve defined by the equation X Y== constant, the axes of Y and of X being respectively the axis of rotation and a line perpendicular thereto,

. means for imparting a uniform rotary motion tothe spindle, a turn-table shaft and :means whereby the turn-table shaft is rotated successively by the rotation of the successive cross-sections of the spindle surface.

, 2'. A driving device for talking and sound recording machines comprising a rotary spindle of progressively increasing radius the surface of whichis generated by the revolution round its axis of rotation of a curve defined by the equation X 1 =constant, the axes of Y and X being respectively the axis of rotation and a lineperpendicular there to, means for imparting a uniform rotary motion to the spindle, a turn-table shaft,

cylindrical means for controlling the said shaft andthread like means adapted to be" coiled round the rotating spindle and to be coiledo'if the cylindrical means.

3. A driving device for talking and sound spindle of progressively increasing radius provided with a substantially spirally wound groove the bottom of which lies on a surface generated by the revolution round its axis of rotation of a curve defined by the equation "X Y -conStant, the axes of. Y and X being respectively the axis of rotation and a line perpendicular thereto, meansfor imparting a uniform rotary fmotion to the spindle, a (turn-table shaft, threadlike means adapted to be wound into the spindle groove and to control the'turn -table shaft.

" provided with a i l. A driving device for talking and sound recording machines comprising a rotary spindle of progressively increasing radius substantially spirally wound groove the bottom of which lies on a surface generated by the revolution round :its axis of rotation of a curve defined by the parting a uniform rotary motion to the spin dle, aturn-table shaft, a cylindrical spirally grooved drumcontrolling the said shaft and threadlike meansadapted to be wound 01f ""the drum groove into the'spindle groove for controlling the turn-table shaft.

5. A driving. device for talking and sound recording machines comprising a rotary tively'said axis of rotation and a line perpen- I dicularthereto, means for imparting a uniform rotary motionltothe spindle, a cylinrecording machines comprising a rotary,

"drical spirally grooved drum the axis of which "is perpendicular to the spindle axis, threadlike means adapted to be wound off the drum groove into the spindle groove for controlling the turntable shaft and means whereby said means are caused to engage tangene, daily the spindle. and the drum always in planesgsubstantially perpendicular to the axes of the spindle and drum respectively.

6. Adriving device for talking and sound recording machines comprising a rotary spins dleof progressively increasing radius pro videdwith an outer substantially spirally wound groove the bottom of which lies on the surface generated by the revolution round the spindle axis of the curve X 1 constant, the axes of Y and X being respectively said axis ofrotation and a line perpendicular thereto,:means forimparting a uniform'rotary'motion to the spindle, a cylindrical spirally grooved drumthe axis of which is perpendicular to the spindle axis. threadlike means adapted to be wound off the drum grooveinto th e spindle groove for controlling the turn-table shaft, means whereby said means are caused to engage the spindlealways in a plane tangent to the groove thereon and means whereby the drum is caused to advance spirally as the thread like means are unwound from it whereby the unwinding point thereof remains stationary in space. Y

7. A driving device for talking and sound recording machines comprisinga rotary spindle of progressively increasing radius provided with an outer substantially spirally wound groove the ,bottomof which lies on the surface generated by the revolution round the spindle axis of the curve X Y=constant, the axes of Yvand X being respectively said axis of rotation and a line perpendicular thereto, means for imparting a uniform rotary mo- 'tion to the spindle, a cylindrical spirally grooved drum the axis of which is perpendicular to the spindle axis, threadlike means. adapted to be wound oft the drum groove into the spindle groove for controlling the turntable shaft, means whereby said means are 7 caused to engage the spindle always in a plane tangent to the groove thereonand means whereby the drum is caused to advance spirally as the threadlike means are unwound from it whereby the unwinding point thereof remains stationary in space, a rotary partadapted to rotate with the drum without advancing longitudinally with it and control means for returning saidpart and thereby the drum to its original position. 7

8. A driving device for talking and sound recording machines comprising a rotary spindle of progressively increasing radius pro 9 vided with an outer substantially spirally wound groove the bottom of which lies on,

the surface generated by the revolution round the spindle axis of the curve X 1 constant,

' the axes of Y and X being respectively said axisof rotation and a line perpendicular thereto, means for imparting'a uniform ro-" tary'motion-to the spindle, acy lindrical spi-v :rally grooveddrum'the axis of which is perpendicular to the spindle axis, threadlike' means ada-ptedfto'be wound off the-drum groove into the spindle groovefor controllingthe turn-table shaft", a pulley for said: a

threadlike means, a support on Which said pulley is 'pivotally secured, means controlled c by the spindle driving means adaptedto make said pulley advance as the threadlike means are-being Woundon to the spindle for causing them to engage said spindle always in a plane tangent to the groove thereon, means controlled by the spindledrivingmeans and 7 adapted to advance the drum spirally as the tlireadlike means are unwoundfrom it Where- Qfl by the unwinding point thereof remains stationaryin space; m f p In testimony. whereoftfhave signedmy name toIthisspecific-ation. 1 Y e I LOUIS' LAURENT CHARLES JAFFARD. 7 

